Skip Navigation LinksSkip Navigation Links
Centers for Disease Control and Prevention
Safer Healthier People
Blue White
Blue White
bottom curve
CDC Home Search Health Topics A-Z spacer spacer
Blue curve MMWR spacer

Persons using assistive technology might not be able to fully access information in this file. For assistance, please send e-mail to: Type 508 Accommodation and the title of the report in the subject line of e-mail.

Public Health Dispatch: Update: Unexplained Deaths Following Knee Surgery --- Minnesota, 2001

Since November 13, 2001, the Minnesota Department of Health (MDH), in collaboration with CDC, has been conducting an investigation of three patients who died unexpectedly within 1 week following knee surgery (1). Patient 1 had received a knee osteochondral allograft, and patients 2 and 3 had undergone total knee replacement surgery. Epidemiologic and microbiologic investigations have not linked the deaths of the three patients.

Blood cultures obtained from patient 1 before his death grew a clostridial species that was identified subsequently at MDH and CDC as Clostridium sordellii by biochemical and molecular typing. Blood cultures from patients 2 and 3 did not yield growth of any bacteria. Molecular and special studies have not identified any Clostridium species in autopsy tissues from patients 2 and 3, and the cause of death in these patients remains unexplained. On the basis of investigative findings, MDH lifted a moratorium on elective knee surgery on November 25.

As of December 4, neither surveillance in Minnesota by MDH nor enhanced case finding by CDC outside of Minnesota and follow-up of reports to CDC have identified any additional cases of C. sordellii infection associated with severe hemodynamic collapse or death in patients recently undergoing knee or large joint surgery. Because infection associated with contaminated graft tissue is a known but uncommon complication of allograft surgery (2), MDH, CDC, and the Food and Drug Administration have initiated an investigation to determine whether the osteochondral allograft might have been the source for the C. sordellii found in patient 1. Nonimplanted knee tissue from the same donor source as the allograft used in patient 1 was obtained by CDC from the same tissue bank. Preliminary cultures of this tissue have yielded growth of Clostridium species; biochemical and molecular testing to identify the species is under way. Reports of other allograft recipients infected with clostridial species have been received at CDC and are being investigated.

Clinicians should consider possible clostridial infection in patients with evidence of infection following allograft implantation. Clinical evaluation should include looking for symptoms and signs of sepsis, including fever, hemodynamic compromise, and/or abdominal pain. In some patients, only local symptoms (e.g., knee pain) may be present during the early course of infection. Diagnostic evaluation should include two sets of blood cultures for both aerobes and anaerobes; these cultures should be incubated for 7 days. If appropriate, other specimens (e.g., knee aspirate or tissue) should be obtained and cultured aerobically and anaerobically. If appropriate, health-care providers should consider expanding empiric therapy to include anaerobic coverage. Consultation with an infectious disease physician might be helpful.

Health-care providers should report cases of clostridial infection following allograft implantation to their state health department or CDC's Division of Healthcare Quality Promotion, telephone 800-893-0485.

Reported by: KH LeDell, MPH, R Lynfield, MD, RN Danila, PhD, HF Hull, MD, State Epidemiologist, Minnesota Dept of Health. Div of Healthcare Quality Promotion, National Center for Infectious Diseases; and EIS officers, CDC.


  1. CDC. Unexplained deaths following knee surgery---Minnesota, November 2001. MMWR 2001;50:1035--6.
  2. CDC. Septic arthritis following anterior cruciate ligament reconstruction using tendon allografts. MMWR 2001;50:1081--3.


Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services.

References to non-CDC sites on the Internet are provided as a service to MMWR readers and do not constitute or imply endorsement of these organizations or their programs by CDC or the U.S. Department of Health and Human Services. CDC is not responsible for the content of pages found at these sites.

Disclaimer   All MMWR HTML versions of articles are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the electronic PDF version and/or the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to

Page converted: 12/6/2001


Safer, Healthier People

Morbidity and Mortality Weekly Report
Centers for Disease Control and Prevention
1600 Clifton Rd, MailStop E-90, Atlanta, GA 30333, U.S.A


Department of Health
and Human Services

This page last reviewed 12/6/2001